File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/include/net/ip6_tunnel.h b/include/net/ip6_tunnel.h
new file mode 100644
index 0000000..9c2c044
--- /dev/null
+++ b/include/net/ip6_tunnel.h
@@ -0,0 +1,105 @@
+#ifndef _NET_IP6_TUNNEL_H
+#define _NET_IP6_TUNNEL_H
+
+#include <linux/ipv6.h>
+#include <linux/netdevice.h>
+#include <linux/if_tunnel.h>
+#include <linux/ip6_tunnel.h>
+
+#define IP6TUNNEL_ERR_TIMEO (30*HZ)
+
+/* capable of sending packets */
+#define IP6_TNL_F_CAP_XMIT 0x10000
+/* capable of receiving packets */
+#define IP6_TNL_F_CAP_RCV 0x20000
+/* determine capability on a per-packet basis */
+#define IP6_TNL_F_CAP_PER_PACKET 0x40000
+
+struct __ip6_tnl_parm {
+	char name[IFNAMSIZ];	/* name of tunnel device */
+	int link;		/* ifindex of underlying L2 interface */
+	__u8 proto;		/* tunnel protocol */
+	__u8 encap_limit;	/* encapsulation limit for tunnel */
+	__u8 hop_limit;		/* hop limit for tunnel */
+	__be32 flowinfo;	/* traffic class and flowlabel for tunnel */
+	__u32 flags;		/* tunnel flags */
+	struct in6_addr laddr;	/* local tunnel end-point address */
+	struct in6_addr raddr;	/* remote tunnel end-point address */
+
+	__be16			i_flags;
+	__be16			o_flags;
+	__be32			i_key;
+	__be32			o_key;
+};
+
+struct ip6_tnl_dst {
+	seqlock_t lock;
+	struct dst_entry __rcu *dst;
+	u32 cookie;
+};
+
+/* IPv6 tunnel */
+struct ip6_tnl {
+	struct ip6_tnl __rcu *next;	/* next tunnel in list */
+	struct net_device *dev;	/* virtual device associated with tunnel */
+	struct net *net;	/* netns for packet i/o */
+	struct __ip6_tnl_parm parms;	/* tunnel configuration parameters */
+	struct flowi fl;	/* flowi template for xmit */
+	struct ip6_tnl_dst __percpu *dst_cache;	/* cached dst */
+
+	int err_count;
+	unsigned long err_time;
+
+	/* These fields used only by GRE */
+	__u32 i_seqno;	/* The last seen seqno	*/
+	__u32 o_seqno;	/* The last output seqno */
+	int hlen;       /* Precalculated GRE header length */
+	int mlink;
+};
+
+/* Tunnel encapsulation limit destination sub-option */
+
+struct ipv6_tlv_tnl_enc_lim {
+	__u8 type;		/* type-code for option         */
+	__u8 length;		/* option length                */
+	__u8 encap_limit;	/* tunnel encapsulation limit   */
+} __packed;
+
+struct dst_entry *ip6_tnl_dst_get(struct ip6_tnl *t);
+int ip6_tnl_dst_init(struct ip6_tnl *t);
+void ip6_tnl_dst_destroy(struct ip6_tnl *t);
+void ip6_tnl_dst_reset(struct ip6_tnl *t);
+void ip6_tnl_dst_set(struct ip6_tnl *t, struct dst_entry *dst);
+int ip6_tnl_rcv_ctl(struct ip6_tnl *t, const struct in6_addr *laddr,
+		const struct in6_addr *raddr);
+int ip6_tnl_xmit_ctl(struct ip6_tnl *t, const struct in6_addr *laddr,
+		     const struct in6_addr *raddr);
+__u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw);
+__u32 ip6_tnl_get_cap(struct ip6_tnl *t, const struct in6_addr *laddr,
+			     const struct in6_addr *raddr);
+struct net *ip6_tnl_get_link_net(const struct net_device *dev);
+int ip6_tnl_get_iflink(const struct net_device *dev);
+
+static inline void ip6tunnel_xmit(struct sock *sk, struct sk_buff *skb,
+				  struct net_device *dev)
+{
+	struct net_device_stats *stats = &dev->stats;
+	int pkt_len, err;
+
+	memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
+	pkt_len = skb->len - skb_inner_network_offset(skb);
+	err = ip6_local_out(dev_net(skb_dst(skb)->dev), sk, skb);
+
+	if (net_xmit_eval(err) == 0) {
+		struct pcpu_sw_netstats *tstats = get_cpu_ptr(dev->tstats);
+		u64_stats_update_begin(&tstats->syncp);
+		tstats->tx_bytes += pkt_len;
+		tstats->tx_packets++;
+		u64_stats_update_end(&tstats->syncp);
+		put_cpu_ptr(tstats);
+	} else {
+		stats->tx_errors++;
+		stats->tx_aborted_errors++;
+	}
+}
+#endif